Pump or compressor



May 17, 1938.

R. STEVENS PUMP OR COMPRESSOR (Ittornegs 2 Sh eets-Sheet 1 Filed Dec.28, 1956 May 17, 1938. R STEVENS 2,117,521

PUMP OR COMPRESSOR Filed Dec. 28, 1936 2 Sheets-Sheet 2 ZhwcntorOttornegs a e l) Patented May 17, 1938 UNITED STATES PATENT, oFFicE2,117,521 PUMP on COMPRESSOR Application December 28, 1936, Serial No.117,686

3 Claims.

This invention relates to a pump or compressor of the angle piston typewherein a plurality of cylinders is provided within which cylinders bothends of all of the pistons reciprocate, and an object of the presentinvention is to provide a device for the purpose which is of simpleconstruction, cheap to manufacture and efiicient in operation, and inwhich there are no valves, the cylinder structures having ports andbeing rotatable in contact with fixed heads formed with inlet andexhaust passages to control the inlet to and outlet from the cylinders.

It is also an object to provide a central guide and support for thecylinder structures, and to provide means for yieldingly holding saidcylinder structures in firm contact with said fixed heads to preventleakage; a further object being to reduce friction and provide a verycompact construction which is light in weight and in which all movingparts are enclosed, making the device especially adapted for use inconnection with household mechanical refrigerators.

A further object is to provide certain other new and useful features,all as hereinafter more fully set forth and shown in the accompanyingdrawings, wherein- Figure 1 is a side elevation of a pump or compressorillustrative of an embodiment of the present invention;

Fig. 2 is a longitudinal section substantially upon the line 22 of Fig.1;

Fig. 3 is a cross section upon the line 3--3 of Fig. 2

Fig. 4 is a similar cross secetion upon the line i4 of Fig. 2;

Fig. 5 is a detail showing one of the cylinder assemblies detached, and

Fig. 6 is an end elevation of Fig. 5.

As shown, the device includes an outer fixed casing formed with twohalves I and 2, the-lower half being provided with a base 3 forsupporting the structure and the ends of this casing are closed by heads4 and 5, each formed with an inlet passage 6 and an outlet passage I.The two halves of the casing are firmly secured together by means ofvertical bolts 8 and the heads 4 and 5 are secured to the ends of thecasing by cap screws 9. The inner end portions of the inlet passages 6and the outlet passages I are formed with extensions In each of whichextends in a semi-circular path concentric with the axis of the head,opening through the inner side of each head.

The casing which is formed by the halves I and 2, is of right angularconstruction, one end portion extending substantially at right angles tothat of the other end portion, and within these ends of this casing arecylinder structures, each indicated as a whole by the numeral II andeach comprising a plurality of tubes each forming a separate cylinder 12and these cylinders are arranged about an axial guide tube I3 and all ofthese tubes are welded together with one end of each tube firmly weldedin end abutting relation, to a suitable head or disk 4 with a pluralityof ports or holes I5, one opening axially into the end of each of thecylinders I2, and each head I4 is formed with a larger axial opening IIiforming a continuation of the bore of the tube I3.

To center each of the cylinder assemblies II Within the ends of thecasing and support each with the outer face of its end disk or head I Ifirmly seated upon the inner face of each of the heads 43 and 5 and withthe ports I5 opening into the semi-circular extensions ID of thepassages 6 and l in the heads, is a central guide shaft I? which is bentsubstantally at right angles intermediate its ends and these ends extendinto the guide tubes I3 of the cylinder assemblies. A drive shaft I8extends through a stuffing box I9 on the head 5 and through this headand through the opening I6 in the disk I4, into the outer end of thecenter guide tube I3 with its inner end fastened to the guide tube bymeans of a transverse pin 2% for driving the cylinder assembly by powerapplied to the outer end of the drive shaft. Between the inner end ofthe drive shaft and a block 2!, is a coiled spring 22 in the guide tube,and interposed between this block 2I and the adjacent end of the angleshaft IT is an antifriction ball 23. Power is thus applied to rotate thecylinder assembly within the outer casing and the spring 22 exerts anendwise pressure upon the drive shaft and through the pin 29 to thecylinder assembly, to hold this assem bly with its end disk M in firmcontact with the inner face of the fixed head 5 so that leakage betweenthe cylinder assembly and the end head 5 will be prevented and as theassembly is rotated, the ports iii will be brought into registry withthe semi-circular inlet and outlet ends of the passages 6 and i to openand close these ports as the cylinder assembly is rotated.

A plurality of angle pistons 24 is provided, one for each of thecylinders I 2, each of these pistons comprising a shaft or rod ofuniform diameter with its angularly extending end portions fittingclosely within the bores of the cylinders I2, one end within thecylinder of one of the cylinder assemblies and the other end within thecorresponding cylinder of the other assembly. Therefore as the cylinderassembly at one end is rotated by power applied through the shaft l8,these several pistons will be carried about the axis of that assemblyand will transmit driving power to rotate the corresponding assembly atthe other end of the device which assembly is guided in its rotation bythe central guide shaft l1 and at its outer end by a short shaft 25which is mounted in a hub bearing at its outer end within the head 4and. extends through the cylinder head or disk l4 into the outer end ofthe guide tube 13 to which it is made fast by means of a pincorresponding to the pin 20 so that this central guide shaft 25 iscaused to turn with the cylinder assembly and a spring corresponding tothe spring 22 is interposed between the inner end of this shaft 25 and ablock corresponding to the block 2!, with an anti-friction ballcorresponding to the ball 23 interposed between the end of the centralguide shaft l1 and said block to yieldingly hold this cylinder assemblyin firm end contact with the inner face of he head 4 and with theseports in register with the semi-circular extensions H] of the inlet andoutlet passages 6 and I of this head 4.

Rotation of the cylinder assembly which is driven by the drive shaft 18therefore imparts ro- ,tation to the other cylinder assembly through thepistons 24 by the movement of these pistons ,labout the axis of the twocylinder assemblies and during such rotation, the ends of the pistonsare thereby caused to reciprocate within the several cylinders of bothcylinder assemblies to alternately draw in air or liquid into theseveral cylinders during substantially one-half of their rotation aboutthe axis of the shafts ll, 18 and 25, and discharge this fluid throughthe ports l5 into the'outlet passages in the heads iand 5 during theother half of such rotation.

With this arrangement all of the moving parts are enclosed within thesplit casing formed by the two halves i and 2 and the assembly of thedevice is greatly facilitated by thus splitting the casinglongitudinally so that the two cylinder assemblies with the anglepistons in place, may be readily placed within the outer casing and thenthe heads 4 and 5 secured in place upon the ends of the casing. Thesprings 22 exert a force to hold the cylinder assemblies firmly seatedagainst the inner surfaces of the heads 4 and 5 and the balls 23 takethis end thrust against the ends of the central guide shaft I! toeliminate friction and'consequent resistance to the rotation of thecylinder assemblies relative to the central guide shaft IT. Thearrangement of the several ports i5 for the several cylinders of eachcylinder assembly provides for the free escape of fluid and its inlet toeach cylinder when its port comes into registry with one or the other ofthe segmental end portions ll] of the inlet and exhaust passages in theadjacent casing head and such port remains open through the length ofsuch segmental passage so that throughout the major portion of eachexhaust stroke of each piston the fluid will freely escape and in a likemanner, substantially throughout the length of the intake stroke of eachpiston, its port !5 will remain open. Therefore each piston will draw influid as it passes about the axis of rotation of the cylinder assemblyat one side and will exhaust fluid as it passes around the other side ofthe assembly, the intake and exhaust being cut off as its port passesover the spaces between the adjacent ends of the segmental end portionsof the inlet and exhaust passages.

With this arrangement and construction, all moving parts are housedwithin a fluid tight casing so that no fluid which may pass by thepistons can escape, the only possible place of escape being through thestuffing box i9, and all parts may be well lubricated and as there areno gears or reciprocating valves, the operation is substantiallynoiseless and is very efiicient in operation as it may be run at highspeeds to produce the desired volume without setting up materialvibration or undue friction.

Having thus fully described my invention what I claim is:

1. In a device of the character described, the combination of a casinghaving end portions extending in angular relation to each other andprovided with end heads formed with inlet and exhaust passages, acylinder structure rotatable within each end of said casing in endcontact with said casing heads, each cylinder structure comprising aplurality of cylinders arranged about the longitudinal axis of thestructure, each structure being also formed with a longitudinal axialbore, a central angular guide shaft with its ends projecting into theaxial bores of said cylinder structures to support and guide saidstructures, straight shafts mounted within said casing heads with theirinner ends extending into the outer ends of the axial bores of thecylinder structures and secured thereto, and coiled springs in saidaxial bores interposed between the ends of said central and straightshafts for yieldingly holding each of said cylinder structures in endabutting relation with the adjacent casing head.

. 2. A pump or compressor comprising a casing, end heads for said casingformed with inlet and exhaust passages, a cylinder structure rotatablewithin each end of said casing and each provided with a head formed withports opening into the outer ends of said cylinders and adapted toregister with said passages in said heads, a plurality of rigid pistonshaving end portions extending in angular relation to each other, one endportion of each piston being adapted to engage within a cylinder of oneof the cylinder structures and its opposite end portion being adapted toengage within a corresponding cylinder of the other cylinder structure,said pistons being arranged for rotation about the longitudinal axes ofsaid cylinder structures, each of said cylinder structures having alongitudinal axial bore, a central guiding and supporting shaft havingend portions extending in angular relation and engaging within saidcentral bores of said cylinder structures to support and guide theadjacent ends of said structures, a drive shaft extending into the outerend of the axial bore of one of said cylinder structures, means forsecuring the inner end portion of said last named shaft to said cylinderstructure to rotate the same, a short shaftmounted at its outerendwithin abearing in the casing head for free rotation therein andextending into the axial bore of the adjacent cylinder structure andsecured thereto to rotate therewith and guide the outer end of saidstructure in its rotation within the casing, and a coiled spring withinthe central bore of each cylinder structure and interposed between theends of said center guide shaft and the ends of said drive shaft andshort shaft to yieldingly hold said cylinder structures in end abuttingrelation with said casing heads.

3. A pump or compressor comprising an outer casing having end portionsextending at right angles to each other, a head for each end of saidcasing, said heads being each formed with inlet and outlet passageshaving inner end portions curved concentrically with the axis of eachhead, a cylinder structure mounted within each end of said casing andformed With a plurality of cylinders arranged concentrically about thelongitudinal axis of each structure, a disk forming a head for eachcylinder structure and provided with ports, one for each of saidcylinders adapted to register with said curved end portions of saidpassages in said casing heads, a plurality of pistons each having endportions extending at right angles to each other and adapted toreciprocate within corresponding cylinders of said cylinder structuresand adapted to rotate about the axes of said structures within saidcylinders, said cylinder structures being each provided with alongitudinal extending central axial tube about which said cylinders arearranged in parallelism therewith, an angle shaft having end portionsextending into the adjacent ends of said central tubes of saidassemblies for guiding and supporting the inner ends of said assemblies,a driving shaft mounted in an axial bearing of one of the casing headswith its inner end extending into said central tube of said adjacentcylinder assembly, means carried by the inner end of said drive shaftfor connecting the same to said cylinder assembly to rotate saidassembly and through said assembly to transmit rotation by means of saidpistons, to rotate the other of said cylinder assemblies, a short guideshaft mounted within a bearing in the casing head adjacent the other ofsaid assemblies and secured to said central tube of said assembly torotate therewith, a coiled spring within said central tube of eachassembly to beer at each end upon an end of one of the said shaftsextending into the outer ends of said tubes for yieldingly holding eachassembly in end abutting contact with said heads of said casing, andanti-friction means interposed between the ends of said angle shaft andsaid springs.

ROY STEVENS.

